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Active, not recruitingNCT04987138BREEZEUpdated Apr 11, 2024

Safety and Effectiveness Study of the Zenflow Spring System

An interventional study of Zenflow Spring System and Sham Procedure in BPH (Benign Prostatic Hyperplasia) and Lower Urinary Tract Symptoms (LUTS), sponsored by Zenflow, Inc.. Active, not recruiting at 7 sites in United States. Open to male participants aged 45 Years and older. Per ClinicalTrials.gov, last updated 2024-04-11.

Sponsored by Zenflow, Inc. · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Primary completion was expected by Jun 2024, 2 years 4 months ago, but the record still lists the study as active, not recruiting.
Phase
Not applicable
Study type
Interventional
Enrollment
279
Allocation
Randomized
Ages
45 Years and older
Sex
Male
01

Study summary

Evaluate the safety and effectiveness of the Zenflow Spring System in relieving LUTS associated with BPH.

Read the detailed description

Prospective, multi-center, multinational, 2:1 randomized, single-blinded, controlled clinical trial of the Zenflow Spring System.

Patients randomized to the treatment group will undergo Zenflow Spring placement.

Patients randomized to the control group will undergo a Sham procedure. Patients and site personnel administering follow-up assessments will be blinded to the randomized treatment through completion of the 3-month follow-up visit. Once a patient has completed their 3-month follow-up assessments, they will be unblinded. Following unblinding, patients who received a Sham procedure may elect to receive treatment with the Zenflow Spring System or alternatively they may exit the study.

The duration of study participation is 60 months for patients who receive a Spring Implant and 3 months for subjects in the Control Arm.

02

Conditions studied

  • BPH (Benign Prostatic Hyperplasia)
  • Lower Urinary Tract Symptoms (LUTS)
03

In context

Prostatic Hyperplasia

827 studies on the registry are indexed under Prostatic Hyperplasia; 179 are open to participants now.

This study's planned enrollment of 279 is above the median of 92 across 626 interventional studies indexed under Prostatic Hyperplasia.

Browse Prostatic Hyperplasia studies →

Lead sponsor

Zenflow, Inc. is the lead sponsor of 7 studies on the registry; 3 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
45 Years and older
Sexes eligible
Male
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Subject is able and willing to comply with all the assessments of the study,
  2. Subject or subject's legal representative has been informed of the nature of the study, agrees to participate and has signed the form,
  3. ≥ 45 years of age,
  4. Baseline IPSS score ≥ 13; ≥ 1 in the IPSS voiding to storage sub-score ratio (IPSS-V/S),
  5. Prostate volume 25 - 80 cc by transrectal ultrasound (TRUS), measured within 120 days post study consent,
  6. Prostatic urethral length between 25 and 45 mm, as measured by cystoscopic pull-back,
  7. Failed, intolerant, or subject choice to not take a medication regimen for the treatment of LUTS.

Exclusion criteria

Exclusion Criteria:

  1. Obstructive intravesical median prostatic lobe as determined by ultrasound (i.e., more than 10 mm intravesical prostatic protrusion on sagittal mid-prostate plane via abdominal ultrasound),
  2. High bladder neck with the absence of lateral lobe encroachment indicating a high likelihood of primary bladder neck obstruction as determined by the Investigator,
  3. Urethral stricture, meatal stenosis, or bladder neck stricture - either current or recurrent,
  4. Anatomical anomalies that will not accommodate the Implant, as determined by cystoscopy (e.g., prostatic urethral length to height geometry),
  5. Requires indwelling catheter or intermittent catheterization to void,
  6. Baseline PSA > 10 ng/mL or confirmed or suspected prostate cancer (Subjects with a PSA level above 2.5 ng/mL, or age specific, or local reference ranges should have prostate cancer excluded to the Investigator's satisfaction),

  7. One of the following baseline test results, taken from a single uroflowmetry reading:

    1. Urinary volume void ≤ 125mL (pre-bladder urinary volume of ≥ 150 mL required),
    2. Peak urinary flow rate (Qmax) of ≤ 5 ml/second or > 15 mL/second,
    3. Post- void residual volume (PVR) > 250 mL
  8. History of other diseases causing voiding dysfunction including urinary retention (e.g., uncontrolled diabetes, diagnosis of neurogenic bladder, Parkinson's disease, multiple sclerosis, etc.),
  9. Subjects with overactive bladder in the absence of benign prostatic obstruction,
  10. Acute urinary tract infection (UTI) or finding of asymptomatic bacteriuria (Note: subject can be enrolled if the UTI is treated and followed with a negative urine test result), or subjects with history of recurrent UTIs (defined as > 3 UTIs in the past 12 months),
  11. Concomitant bladder stones,
  12. Previous pelvic irradiation or radical pelvic surgery,
  13. Previous prostate surgery, including: enucleation, resection, vaporization, thermotherapy, ablation, stenting or prostatic urethral lift,
  14. Chronic prostatitis, recurrent prostatitis, chronic pelvic pain syndrome (CPPS), or painful bladder syndrome within the past 12 months
  15. Known allergy to nickel,
  16. less than 60 months,
  17. Use of concomitant medications (e.g., anticholinergics, antispasmodics or tricyclic antidepressants) affecting bladder function,
  18. Inability to stop taking anticoagulants and/or antiplatelets for at least 3 days prior to the procedure or coumadin for at least 5 days prior to the procedure (Note: low dose aspirin therapy (81 mg) is permitted),
  19. Taking 5-alpha-reductase inhibitors within 3 months of baseline evaluation,

  20. Taking one of the following within 2 weeks of baseline evaluation:

    1. alpha-blockers,
    2. imipramine,
    3. anticholinergics,
    4. cholinergic gonadotropin releasing hormonal analogues,
    5. Phosphodiesterase-5 Enzyme Inhibitors (Tadalafil) in doses for BPH,
    6. Beta-3 adrenergic receptor agonist (Mirabegron),
  21. Taking androgens, unless eugonadal state for at least 3 months or greater as documented by the Investigator,

  22. Taking one of the following within 24 hours of pre-treatment (baseline) evaluation:

    1. phenylephrine, or,
    2. pseudoephedrine,
  23. Future fertility concerns, or,
  24. In the Investigator's opinion, the subject has a physical, psychological, or medical impairment that might prevent study completion or would confound study results (including subject questionnaires).
Terms in these criteria, in plain language(2)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Life expectancy

The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.

05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Triple (Participant, Care provider, Outcomes assessor)
Enrollment
279 participants (estimated)

Study arms

  • Other
    Roll-in Cohort

    Each Investigator will be allowed to treat up to 3 roll-in subjects with the Spring Implant prior to initiation of randomization. Roll-in patients will be followed for 60 months.

    Device: Zenflow Spring System

  • Active comparator
    Treatment Arm

    Includes all patients who are randomized and start the treatment procedure. During the procedure the patient will be shielded from the treatment area and cystoscopy screen. The patient and site personnel administering follow-up assessments will be blinded to the study arm through the 3-month follow-up visit. Unblinding will occur at 3 months post-procedure after the assessments are completed. Follow up will continue for 60 months.

    Device: Zenflow Spring System

  • Sham comparator
    Control Arm

    Includes all patients who receive a sham procedure. Patients will be shielded from the treatment area and cystoscopy screen. A Foley Catheter is placed into the patient's bladder and inflated. Additionally, devices will be used to produce mock deployment sounds of the Zenflow procedure. Once complete, the balloon will be deflated and the catheter will be removed, completing the procedure. Control arm subjects are followed for 3 months and exited from the study unless they elect and qualify for Crossover.

    Device: Sham Procedure

  • Other
    Crossover Cohort

    Control Arm (Sham) patients can receive treatment with the Zenflow Spring System after their 3-month follow-up assessments are completed, and their symptoms warrant treatment and enrollment criteria are met. The study visit follow-up schedule will restart and the subject will be followed for 60 months post Zenflow Spring implantation. Unless treated with the Spring System, the subject will be exited from the study once they have completed their 3-month follow-up visit.

    Device: Zenflow Spring System

Interventions

  • DeviceZenflow Spring System

    The Zenflow Spring Implant is an electropolished and passivated nickel titanium alloy (nitinol) implant. The implant is constructed from a single wire strand formed into ring elements connected by spine sections. There are four sizes of implants ranging from 16 mm to 24 mm in length and 14 mm to 16 mm in diameter to implant in the subject's prostatic urethra. The implant is placed in the urethra using a custom delivery catheter and cystoscope (Spring Scope). The implant is intended to be permanent but can be removed if necessary.

  • DeviceSham Procedure

    A18 Fr Foley Catheter is placed into the patient's bladder. To mimic the Treatment Arm procedure, the Foley Catheter balloon will be inflated in the bladder. Once inflated, slight tension will be applied against the subject's bladder neck. While tension is being applied the site staff will follow a script to simulate the Zenflow procedural steps. Additionally, devices will be used to produce mock deployment sounds of the Zenflow procedure. Once complete, the balloon will be deflated and the catheter will be removed, completing the procedure.

    Also known as: Foley Catheter

06

What researchers measure

Primary outcomes

  1. Safety - The need for urinary catheterization

    The rate of extended post-operative urinary catheterization (\> 7 days from treatment) for inability to void among patients treated with the Zenflow Spring System.

    Time frame: Greater than 7 days after procedure

  2. Safety - Adverse Events

    The rate of device or procedure related serious adverse events in both the Treatment Arm and the Sham Arm.

    Time frame: Procedure through 12 months

  3. Effectiveness of the Spring Implant in reducing symptoms of Benign Prostatic Hyperplasia (BPH) as compared to Sham

    The Treatment Arm will be considered superior to the Control Arm (Sham) when the mean 3-month improvement from baseline score for the IPSS symptom questionnaire demonstrates a minimum statistical margin of 25% compared to mean improvement from baseline for the Control Arm (Sham) alone.

    Time frame: Procedure to 3 months

  4. Effectiveness- Symptoms Improvement

    The mean percent change in IPSS in the treatment arm is at least 30% improvement over the Patient's pre-treatment baseline score.

    Time frame: Procedure to 12 months

Secondary outcomes

  1. Safety - Adverse Events

    Rate of device or procedure related adverse events at all time points.

    Time frame: Procedure through 60 months

  2. Safety - Pain Assessment Questionnaire

    Comparison of pain at discharge to 2-week, 1- and, 3-month follow-up visits per Visual Analogue Scale (VAS) questionnaire. The VAS questionnaire asks the patient to indicate on a scale of 1 to 10 his level of pain where 1 is no pain and 10 is the worst pain.

    Time frame: Procedure through 3 months

  3. Safety - Sexual Health Questionnaire 1

    Change in sexual health characterized by the questionnaire Sexual Health Inventory for Men (SHIM).

    Time frame: 3 months post procedure through 24 months post procedure

  4. Safety - Sexual Health Questionnaire 2

    Change in sexual health characterized by questionnaire Male Sexual Health Questionnaire - Ejaculatory Domain (MSHQ-EjD)

    Time frame: 3 months post procedure through 24 months post procedure

  5. Safety - Device Removal

    Assessment of adverse events outcomes related to a Spring Implant removal procedure.

    Time frame: Procedure through 60 months

  6. Safety - Classification of Adverse Events

    Proportion of patients with adverse events classified as Clavien-Dindo Grade IIIb or higher or any event resulting in persistent disability

    Time frame: Procedure through 3 months

  7. Effectiveness - long term symptom improvement 1

    Percent of patients who experience at least a 30 percent improvement in IPSS from their baseline pre-treatment score

    Time frame: Procedure through 12 months

  8. Effectiveness - long term symptom improvement 2

    Mean percent change in IPSS in the treatment arm compared to baseline at all timepoints other than the primary endpoints.

    Time frame: Procedure through 60 months

  9. Effectiveness - flow metrics

    Change from baseline in uroflowmetry measures of peak flow rate (Qmax)

    Time frame: 1 month post procedure through 60 months

  10. Effectiveness - Re-intervention (device)

    Post-procedure incidence of secondary reintervention using an alternate surgical LUTS therapy.

    Time frame: Procedure through 60 months

  11. Effectiveness - Re-intervention (drug)

    Post-procedure incidence of secondary reintervention using standard pharmacological agents for LUTS therapy.

    Time frame: Procedure through 60 months

07

Study locations

7 sites
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Sep 2021 (actual). Primary completion is estimated for Jun 2024, 33 months after the start.

Of 51 industry-sponsored interventional studies with no phase under Prostatic Hyperplasia, half reached primary completion within 30 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 50. This study's planned 33 months is close to that.

Counting every sponsor, half of 203 studies reached it within 26 months; a quarter within 14 and three quarters within 48.

How these figures are worked out, and which studies are left out of them.

Registered
Jul 13, 2021
First posted
Aug 3, 2021
StartActual
Sep 30, 2021
Primary completionEst.
Jun 30, 2024
CompletionEst.
Jun 2026
Last update
Apr 11, 2024
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Apr 11, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04987138
Lead sponsor
Zenflow, Inc.
Responsible party
Sponsor
First posted
Aug 3, 2021
Start date
Sep 30, 2021
Primary completion
Jun 30, 2024 (estimated)
Completion
Jun 2026 (estimated)
Last update
Apr 11, 2024

Study contacts

Claus Roehrborn, M.D
principal investigator · UT Southwestern, Dallas, TX

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
Yes
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Apr 2024. You cannot join it, but the record below documents what was studied.

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Discussion

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